Measuring Frequency Characteristics of PCBs with Modal Reservation before and after Open Circuit Failure under Climatic Impact

This paper considers the frequency dependences of the S-parameters for printed circuit boards with modal reservation before and after the open circuit failure. Two board prototypes (with modal reservation before and after failure) were designed to experimentally study their features. The frequency dependences of S-parameters were obtained for both of them at different temperatures. It was revealed that the level of transmission ratio for the board with modal reservation before and after failure is almost the same and the effect of MR will remain after failure without affecting the useful signal except at high temperature. Moreover, all S-parameters of the prototypes decrease with increasing the temperature and increase with decreasing the temperature compared to the results obtained at the room temperature over the entire frequency range except for the resonance frequencies. This study confirms that the radioelectronic devices which use the modal reservation layout and tracing approach can work under almost any climatic conditions even after failure which in turn will improve their reliability and immunity against any interference. However, the useful signal frequency range can be decreased considerably, which must be controlled.